A numerical study of rock scratch tests using the particle-based numerical manifold method

A better understanding of the rock-tool interaction is necessary to improve the cutting efficiency. In this paper, we present a numerical study of rock scratching using a newly developed particle-based numerical manifold method (PNMM). The scratching processes with different cutting depths are first simulated, where the failure pattern and cutting force are discussed. The transition of brittle-ductile failure with an increased cutting depth is reproduced. It is validated that when the cutting depth is intermediate, rock scratching presents a transitional mode between ductile and brittle failure. Then, a parametric study is performed by a series of numerical simulations. The effect of cutter operational parameters on the cutting force and energy consumed by the cutter are studied. Three operational parameters of the cutter are considered in this study, including the cutting depth, cutting speed, and cutter rake angle. An estimation of the transitional cutting depth range is given by the result of the mechanical specific energy of the cutter. Besides, some advice is provided to improve the efficiency of rock cutting in engineering practice.